The present invention relates to a take-up reel on which a veneer sheet in a damp state as cut by a veneer lathe, or a veneer sheet that has been dried from the damp state thereof by a dryer is wound, a veneer reeling apparatus that reels the veneer sheet, a tape feeding unit that feeds a tape into between veneer sheets which is reeled into a veneer roll and a veneer roll unwinding apparatus that automatically unwinds a veneer sheet from a veneer roll wound on the take-up reel to send the veneer sheet to a next step and a production method for laminated wood.
It is an object to provide a take-up reel on which a veneer sheet in a damp state as cut by a veneer lathe, or a veneer sheet that has been dried from the damp state thereof by a dryer is wound and a veneer reeling apparatus that winds a veneer sheet on a take-up reel in a smooth manner while preventing cracks, rifts or the like in directions of fibers of the veneer sheet from occurring. It is another object to provide a tape feeding unit that feeds a tape into between veneer sheets from a tape roll and can cut the tape at an arbitrary timing. It is still another object to provide a veneer roll unwinding apparatus that automatically unwinds a veneer sheet from a veneer roll wound on the take-up reel to send the veneer sheet to a next step.
According to findings from experiments conducted by the present inventors, when a take-up reel (a diameter of 165 mm) that has been used for reeling a veneer sheet before drying, that is a veneer sheet as cut from a log, is used for reeling a veneer sheet after drying with no special consideration, there have been many of cases where the veneer sheet after drying does not adapt itself to a small diameter of the take-up reel and as a curvature of a winding circumferential surface of a take-up reel is smaller as compared with a thickness of the veneer sheet to be wound, cracks are easier to occur in parallel to fiber directions, thereby making it impossible for the veneer sheet to be wound on the take-up reel. Especially, when there are cracks, rifts or the like generated in a veneer sheet after drying, tearing and breaking occur from such defects. The inventors have acquired a way to determine a diameter of a take-up reel on which a veneer sheet after drying is wound in connection with a thickness T of the veneer sheet based on the findings from experiments: A diameter of a take-up reel as a curvature corresponding to a thickness T of a veneer sheet is given based on a ratio of a diameter D of a take-up reel/ a thickness T of a veneer sheet wound thereon and the minimum diameter of a take-up reel is set to 300 mm. According to the way to determine a diameter of a take-up reel, a veneer sheet after drying can preferably be wound on a take-up reel having a diameter equal to or more than 85 times a thickness of a veneer sheet and equal to or more than 300 mm.
According to a take-up reel of the invention, a weight of the take-up reel can be reduced and a burden of driving power can be decreased in transportation of a take-up reel, reeling a veneer sheet, storage of a veneer roll in a veneer roll stock area of a reeling deck and so on. Further, a veneer sheet on a winding circumferential surface of the take-up reel has ventilation passages, in radial direction, in communication with spaces formed in the interior of the take-up reel and openings are formed in winding supports for a veneer sheet fixed on a reel shaft to produce communication between the spaces along the reel shaft direction. With such a structure, since the winding circumferential surface of a veneer sheet of the take-up reel and the spaces formed in the interior of the take-up reel communicate with the air outside the take-up reel, ventilation is ensured. Therefore, hot air, moisture and so on included in the veneer sheet after drying is released through many of openings into the outside air and thereby, an equilibrium moisture content of each wound veneer sheet can be accelerated to reach in the storage.
In the take-up reel, flanges disposed at a spatial interval of a length corresponding to a winding width of a veneer sheet are used as winding supports for the veneer sheet and the veneer sheet is wound on the take-up reel to form a veneer roll. In such a situation, air in spaces between the flanges are released into the outside air through openings formed in the flanges and finally openings of the flanges at both outermost sides of the take-up reel. Therefore, hot air, moisture and so on, included in a veneer sheet after drying, wound on the take-up reel are released from spaces between the flanges into the outside air through openings formed in the flanges and finally openings of the flanges at both outermost sides of the take-up reel, while fresh air in the outside air flows into the interior of the take-up reel through the openings of the flanges at both outermost sides of the take-up reel.
A veneer sheet after drying is wound on the take-up reel as a pair of two overlapping veneer sheets with threads as guide to form a composite veneer roll. The composite veneer roll is prepared for combination of a face veneer sheet and a substrate veneer sheet for use in a multi-ply laminated wood and two veneer sheets are superimposed on each other while fiber orientations of the respective sheets are aligned to be the same as each other. The two overlapping veneer sheets are composed of those of different kinds or preferably composed of a face sheet and a substrate sheet, wherein the face and substrate sheets are each selected from various kinds thereof. Further, since face and substrate sheets are almost of the same in grade, two face sheets of the same kind or two substrate sheets of the same kind are sometimes combined to form two overlapping veneer sheets.
Further, pairs of two overlapping veneer sheets and single veneer sheets, both after drying, with a pair of overlapping veneer sheets and a single veneer sheet as a set, are alternately wound on the take-up reel with threads as guide to form a composite veneer roll. The composite veneer roll is prepared for use in five-ply laminated wood, and a pair of two overlapping veneer sheets and a single veneer sheet, both of the same fiber orientation, are combined as a set. The three veneer sheets composing the set can be constituted of those of different kinds from one another or preferably constituted of a face sheet, a substrate sheet and a central core sheet, wherein the face, substrate and central core sheets are each selected from various kinds thereof. Face and substrate sheets in an overlapping state as pairs and single central core sheets are alternately wound on a take-up reel. Further, since face and substrate sheets are almost the same in grade, two face sheets of the same kind or two substrate sheets of the same kind are sometimes combined to form two overlapping veneer sheets.
A veneer reeling apparatus of the invention comprises: a take-up reel installed in a veneer reeling position in a rotatable manner; a drive roller that is disposed below the take-up reel and which transmits a driving force at a variable speed; a veneer dryer installed upstream from the veneer reeling position; a connection conveyor installed between the terminal end of the veneer dryer and the drive roller in the veneer reeling position; and a plurality of thread feeding mechanisms arranged at arbitrary spatial intervals in the length direction of the take-up reel, wherein a continuous veneer sheet that has been dried in a veneer dryer can be wound on the take-up reel with threads in plural rows arranged in the length direction of the take-up reel as guide.
Further, a veneer reeling apparatus of the invention comprises: a take-up reel installed at a veneer reeling position in a rotatable manner; a drive roller that is disposed below the take-up reel and which transmits a driving force at a variable speed; a veneer dryer installed upstream from the veneer reeling position; a direction change-over conveyor installed between the terminal end of the veneer dryer and the drive roller in the veneer reeling position; and a plurality of thread feeding mechanisms arranged at arbitrary spatial intervals in the length direction of the take-up reel, wherein a non-continuous veneer sheet that has been dried in a veneer dryer can be wound on the take-up reel with threads in plural rows arranged in the length direction of the take-up reel as guide.
A winding guide member comprises: for example, endless bands in plural number of rows that each extend over three pulleys disposed at least at three points including a base end section, a middle section and a distal end section. Each endless band is connected to the distal end of a transport conveyor that transports a veneer sheet at a pulley in the base end section. Further, when the pulleys in the distal end section are swung in a direction toward a take-up reel by a following action means, the endless bands get into press contact to part of the circumferential surface of the take-up reel along the curvature thereof.
It should be appreciated that while each endless band is of a belt-like shape that extends over pulleys in the base end section and the distal end section in an endless manner, diameters of the pulleys in the base end and distal end sections are not equal to each other but the pulleys in the base end section are large in diameter as compared with the pulleys in the distal end section. Therefore, when the endless bands are pressed on the lower portion of the circumferential surface of the take-up reel, there arises a spatial margin corresponding to a difference between diameters of both pulleys in the base end and distal end sections, which makes the endless bands press the circumferential surface of the take-up reel over a surface area extending in the reel shaft direction with a width in the lower portion thereof. With such press on the surface area, more of a frictional force can be produced between the endless bands and the lower portion of the circumferential surface of the take-up reel due to increase in contact area, enabling winding of the veneer sheet on the take-up reel in a stable manner. Pairs of support arms are bent in the middle region thereof with the distal end thereof displaced toward the take-up reel, as a diameter of a veneer roll increases with progress in winding operation, the following inconveniences are avoided: such as those that the upper tracks of the endless bands get into contact and interfere with the support arms, between a lower surface and an upper surface, or the endless bands cease circulation, ensuring winding of a veneer sheet on a take-up reel.
Further, when a winding guide member is in a press contact state in conformity with the curvature of part of the circumferential surface of the take-up reel, rotary pulleys provided maintains the winding guide member in a firmly stretching condition under a constant tension by pushing or pulling the endless bands constituting the winding guide member under a pressure while guaranteeing a circulation force of the winding guide member so as to be rotatable all time. Therefore, the winding guide member can run a long the curvature of the take-up reel while imparting almost the same frictional force on a veneer sheet, which enables a stable winding operation.
Especially, it is also possible that the rotary pulleys are individually provided on the endless bands in plural row constituting the winding guide member so as to individually adjust pushing or pulling the endless bands under a pressure while ensuring its circulation force. When firm stretching means are independently provided for the respective endless bands in such a way, it is possible that the endless bands of the winding guide member can individually be maintained in a firm stretching state in the same degree and thereby, a veneer sheet can receive almost the same frictional force at any points on a take-up reel along the shaft direction thereof even if there arise a deflection caused by self weight in the take-up reel or a thickness of a veneer sheet fluctuates in the course of winding operation, for example.
According to a tape feeding unit of the invention, a tape roll is blocked on its movement and controlled on its position in a tape feeding direction by forward movement stopper members on transport means and a tape unwinding from the tape roll that is under such control can be inserted into between veneer sheets that is wound on the take-up reel to form a tape roll. When a veneer sheet is wound on a take-up reel to form a veneer roll in synchronism with a speed at which the veneer sheet is cut from a log by a veneer lathe, the tape can be put in a firm stretching state between the tape roll and the veneer roll. A cutting section of a tape cutting tool is in a sliding contact with the surface of the tape in unwinding and feeding rotation of the tape roll can be stopped at a position where movement of the tape roll is blocked.
Further, a tape feeding unit for a veneer roll which feeds a tape into between veneer sheets that is wound on a take-up reel can comprises:
a vacuum chuck conveyor that guides the tape into between veneer sheets from a feed source;
a tape rack that is provided to a tape feed source, which has a plurality of tape housing rooms not only arranged in a movable manner in a direction almost at a right angle to a tape feed direction of the vacuum-chuck conveyor, but also respectively separated by partition members preventing falling of a tape roll to either of both sides and respectively having tape rolls accommodated therein that are each produced by winding a tape on a core; which is intermittently moved a distance equal to a pitch at which the tape housing rooms are arranged such that each of the tape housing rooms are sequentially located on a transport route of the vacuum-chuck conveyor; and which is operated such that when a tape housing room arrives on the transport route, it is possible that a tape is unwound from a tape roll through the front side thereof that is opened while a tape roll is rotatably supported and simultaneously prevented from falling to either of both sides by partition members; a forward movement stopper member that is disposed in an adjacent manner to the tape rack downstream therefrom on the transport route of the vacuum-chuck conveyor, which stops a tape roll, after a tape housing room of the tape rack comes to be located on the transport route of the vacuum-chuck conveyor, and a tape roll in the tape housing room then moves forward by an extreme extent at which the tape roll does not disengage from partition members, and which controls a position of the tape roll such that the tape is unwound from the tape roll at a place where the tape roll has been stopped while being rotated by the vacuum conveyor;
a tape cutting tool that protrudes from the distal end of the transport means; and
a tape roll rotation stop device that ceases rotation of the tape at a position upstream from the forward movement stopper member.
In such a way, with use of a tape rack, not only is falling of a tape roll to either of both sides prevented from occurring, but the next tape roll can be fed by moving the tape rack over a distance corresponding to a predetermined pitch of partition members when unwinding the preceding tape roll is completed. In this case, a forward movement stopper member can be provided separately and independently from the tape rack, for example, with a position thereof being fixed.
A forward movement stopper member may be one that allows unwinding of a tape roll in a sliding contact with the tape roll while preventing forward movement of the tape roll, but a stopper of a idling roller type is preferably used since the stopper is in a rolling contact with the tape roll and thereby, resistance therebetween of relative movement is minimized. Further, two idling roller stoppers can be used instead of a single idling roller stopper: for example one that is used to be in contact with a tape roll of a large diameter and the other that is used to be in contact with a tape roll of a small diameter.
Further, when winding of a veneer sheet is interrupted or terminated, rotation of a tape roll is ceased by pressing one side of the tape roll in a direction intersecting a direction of tape unwinding from the other side thereof. In this case, as means for stopping rotation of a tape roll, there are provided a receiving member that receives the one side surface of the tape roll and which is erected from a frame of a vacuum-chuck conveyor constituting of the transport means on one side thereof as viewed in a direction intersecting the tape unwinding direction at a position upstream from the forward movement stopper member and a press member connected to a cylinder mounted to the frame, wherein the press member is press-movable to the other side surface of the tape roll. Further, when winding of a veneer sheet is interrupted or terminated, rotation of a tape roll is ceased by pressing the press member to the receiving member while being in contact with the other side surface of the tape roll.
A cutting tool for cutting a tape protrudes from the distal end of the transport means, and not only has a cutting section extending in a direction intersecting the tape feed direction but can move in a direction in which the cutting tool comes into contact with the tape and the cutting section gets into a sliding contact with the tape, which is fed, by a movement mechanism. In order to attain a good sliding contact state, for example, a transport means swings about a fulcrum and thereby, the cutting section of the tape cutting tool goes from a sliding contact state to a state where the section partly presses into the surface of the tape.
While driving of a veneer lathe is ceased almost in synchronism with cease of rotation of a tape roll, a take-up reel continues inertial rotation movement at a veneer reeling position. Therefore, the tape is pulled by the veneer take-up reel that keeps its inertial rotation movement in spite of stoppage of tape unwinding from a tape roll, which causes the tape in a pulled state to be cut at the weakest position thereof, that is a position with which the cutting section of the tape cutting tool is in a sliding contact.
Further, when a tape unwound is twisted, there is a chance to cause a trouble since an adhesive surface of the tape is turned upside down. In order to prevent such a twist of the tape surface, an upside-down turn (twist) preventive member of a spatula-like member by which a twist of the tape surface is corrected or prevented from occurring can be provided at the distal end of the transport means. A tape unwound from the tape roll is pressed on the circumferential surface of a veneer roll by advancing the spatula-like member continuously at regular intervals from when the tape gets inserted into between veneer sheets to when the tape is cut. While a tape unwound from a tape roll being inserted in a normal state is sometimes turned upside down by chance in the course of operation and inserted into between veneer sheets in a wrong state, the twist phenomena can be prevented from occurring by adoption of the twist preventive member.
In a veneer roll unwinding apparatus of the invention, drive guide bands are constituted of endless bands such as belts that extend over a plurality of base end pulleys fixedly mounted on a support shaft located below a unwinding position in the shaft direction thereof at arbitrary spatial intervals and as many distal end pulleys as the number of the base end pulleys, wherein the distal ends at which the distal end pulleys are mounted are free. The distal end pulleys are swingable with the support shaft as a fulcrum and the drive guide bands are moved to or away from the lower portion of the circumferential surface of a veneer roll formed by winding a veneer sheet on a take-up reel which is rotatably disposed at the unwinding position.
Further, relay pulleys whose diameters are larger than those of the base end pulleys are rotatably mounted on a shaft on which the base end pulleys are fixedly mounted in the fold-back side of the drive guide bands, that is in the base end pulley side where a veneer sheet is folded back and turned upside down. It is preferable that the a plurality of relay pulleys are in a freely idling manner disposed on the shaft on which the base end pulleys are fixedly mounted while arranged in lateral direction together with the base end pulleys and a fold-back guide member is provided on the opposite side to the relay pulleys in the fold-back section. The fold-back guide member is preferably constructed of: a frame with an opposite surface to the relay pulleys which surface has a profile of an arc extended along the curvature of the relay pulleys; a plurality of pulleys that are supported on the frame; and endless bands extending over the pulleys. The endless bands extending over the pulleys respectively correspond to the relay pulleys in number and disposed in positions opposite to the positions where the relay pulleys are located, and in sliding contact with the outer circumferential surface of a veneer sheet fold-back side of the relay pulleys.
The endless bands circulates at almost the same speed as that of a transport speed of a veneer sheet transported on the drive guide bands to a fold-back direction. When the drive guide bands circulate in contact with the lower portion of circumferential surface of a veneer roll while swinging with a support shaft as a fulcrum the veneer sheet is unwound by a frictional force of the drive guide bands acting on a veneer roll. The unwound veneer sheet is then transported on the drive guide bands and reach the fold-back section thereof, and then is transferred to the relay pulleys from the drive guide bands. The transferred veneer sheet is folded back by receiving a driving force of the endless bands of the fold-back member while being pinched between the relay pulleys and the endless bands, with the result that the veneer sheet is turned upside down.
In such a way, since a transport speed of the drive guide bands and a fold-back speed at which a veneer sheet is folded back while being pinched between the endless bands constituting the fold-back member and the pulleys in the fold-back section are controlled to be almost the same as each other, there is no chance that a veneer sheet is stretched in a direction perpendicular to fiber orientations of the veneer sheet in company with control of a circumferential speed as described above. Therefore, there arises no excessive concentration of tension at a starting position in unwinding of a veneer sheet when a veneer sheet is unwound from a veneer roll by means of the drive guide bands, thereby preventing breaking and tearing in fiber orientations of a veneer sheet at the starting position in unwinding from occurring.
Further, in a veneer roll unwinding apparatus as described above, a plurality of thread reels are provided in downstream positions from the unwinding position while a travel member is provided in a freely reciprocating manner to or away from the plurality of thread reels with a backward movement limit thereof in an upstream side from the unwinding position. On the travel member, not only there are provided a plurality of grasping members that grasp the terminal ends, which are free fore-ends, of threads that hang down from a veneer roll, wherein the threads are wound on the veneer roll in plural row along the length direction thereof as guide for a veneer sheet, but the grasping members can respectively be provided with nozzles that communicate with an air duct. With such a configuration, the free ends of the threads can be grasped when the travel member advances and the threads are wound on the thread reels by air streams from the nozzles at the travel member forward movement limit. A veneer sheet is unwound by pressing the drive guide bands to part of the circumferential surface of a veneer roll while the threads continues to be wound by the air streams.
Further, in the veneer roll unwinding apparatus, the following configuration can also be adopted: A frame on which a plurality of thread reels are disposed is provided in a downstream side from the unwinding position in a freely reciprocating manner to or away from the unwinding position, wherein the thread reels are disposed at positions on the frame corresponding to threads, which are wound on a veneer roll as guide for a veneer sheet in plural rows along the length direction of the veneer roll, and whose free ends hang down from a veneer roll, and suction holes that communicate with an exhaust duct are respectively formed at winding portions of the thread reels at which threads begin to be wound. In the configuration, the threads are wound on the thread reels by an exhaust stream to the exhaust holes when the frame is positioned at the forward movement limit, thereafter the frame return to its original position and then, a veneer sheet can be unwound from a veneer roll with the drive guide bands in press contact with part of the circumferential surface of the veneer roll while threads continue to be wound on the thread reels.
Further, in the veneer roll unwinding apparatus, the following configuration can also be adopted: A pair of unwinding rollers are disposed at positions downstream from the unwinding position such that both or one of the unwinding rollers can freely be moved to or away from each other, or the other, and the unwinding rollers work for unwinding threads at the positions corresponding to the threads, which are wound on a veneer roll as guide for a veneer sheet in plural rows along the length direction of the veneer roll, and whose free ends hang down from a veneer roll. In the configuration, a veneer sheet can be unwound from a veneer roll with the drive guide bands in press contact with part of the circumferential surface of the veneer roll while the pair of unwinding rollers take up and pinch free ends of threads therebetween by moving to each other and unwind the threads. In this case, it is preferable that one of the pair of unwinding rollers is of a single cylinder, while the other is replaced with a plurality of unwinding rollers on a common axial line each with a same diameter cylinder, wherein the single unwinding roller and the plurality of unwinding rollers can freely be moved to or away from each other.
It should be appreciated that it is preferable that in the drive guide bands, a diameter of base end pulleys is larger than that of distal end pulleys, and pairs of support arms that respectively support the distal end pulleys are each bent in the middle region with the distal end thereof displaced upward.
In unwinding a veneer sheet from a veneer roll in which unwinding assist members constituted of long flexible members are reeled together with a veneer sheet, when a position from which a veneer sheet begins to be unwound from the circumferential surface of the veneer roll is called a veneer sheet separating position and a veneer sheet separation opposite position is set at an opposite point on the circumferential surface of the veneer roll from the veneer sheet separating point, on the other side of the central axial line of the veneer roll from the veneer sheet separating point, a direction along which the unwinding assist members are pulled out from the veneer roll can be determined between the veneer sheet separating position and the veneer sheet separation opposite position in the veneer sheet unwinding side. In the veneer sheet unwinding side formed between the veneer sheet separating position, from which a veneer sheet begins to be unwound from the circumferential surface of the veneer roll, and the veneer sheet separation opposite position, at which a line from the veneer sheet separating position through the center of the veneer roll intersects the circumference of the veneer roll, a direction along which the unwinding assist members, for example the threads, are pulled out from the veneer roll is determined in a space between the veneer sheet separating position and the veneer sheet separation opposite position. It is important that the pulling direction is determined such that when a veneer sheet unwound from the veneer roll tends to be wound on the veneer roll in accompanying manner, the pulling direction works so as to prevent accompanying phenomena of a veneer sheet with the veneer roll from occurring and to be effective for bringing the veneer sheet to the transport surface. That is, when a thread is pulled toward almost directly above along the curvature of the veneer roll or in a direction inclined from the directly above toward the other side from the veneer sheet unwinding side, it is hard to block the accompanying action of a veneer sheet by a thread. Therefore, it is preferable that an angle formed between a line that connects the center of the veneer roll and the veneer sheet separating position and a line that connects the center and a separating point of a thread is less than 90 degrees and a thread is pulled out from the veneer roll with an angle in the range.
A thread support device is located at an outward position radially spaced apart from the circumferential surface of a veneer roll and thread auxiliary pulleys are rotatably mounted on a support shaft thereof disposed in parallel to the central axial of the veneer roll. When threads that are wound on the veneer roll along the curvature are protruded from the veneer roll outwardly, the threads are recovered by supporting on the thread auxiliary pulleys so as to minimize a loss of the threads, wherein the threads are received into a recovery box or onto thread reels in a firmly stretching state of the threads. Further, in supporting the thread auxiliary pulleys, if the thread auxiliary pulleys are rotatably mounted on the fore-ends of protruded arms that protrude from the support shaft, the threads can be supported by the thread auxiliary pulleys with ease.
The support shaft of the thread support device is supported by one ends of arm rods at both ends of the support shaft and one of rotary shafts attached to the other end of the arm rod is mounted to a piston rod of a fluid cylinder. The rotary shaft is swung through an angle by extending or contracting the piston rod, thereby enabling displacement of a position of the support shaft outwardly spaced from the veneer roll along the circumference of the veneer roll. With such a configuration to enable the displacement, the threads are positioned in a protruding manner while being spaced from the veneer sheet unwinding surface of the veneer roll and in addition, in a case where the protruding position is not so much effective for blocking the threads tending to be wound accompanying the circumferential surface of the veneer roll, the position at which the threads are supported spaced outwardly while swinging the rotary shaft is displaced to a position of the support shaft with which the veneer sheets that tends to be wound on the veneer roll are effectively blocked from accompanying the circumferential surface thereof, that is the support shaft is displaced to a position closer to the veneer sheet unwinding surface.